The modules presence and presence_xml were part of default kamailio.cfg, being loaded when WITH_PRESENCE is defined.

In addition, the following modules are loaded:

presence_dialoginfo

pua

pua_dialoginfo

dialog

Besides setting parameters for presence and dialog module, in route[RELAY] is added an IF block for dialog-related requests to publish the states (by setting FLT_DLGINFO flag) and managing dialog with dlg_manage().